Answer:
-0.045
Step-by-step explanation:
you first take the derivate of A(t)
A'(t)=1.4e^-0.05t X (-0.05)
A'(t)=-0.07e^-0.05t
so when t=0
amount remaining is -0.07e^-0.05(0) ---- e^0 = 1
so its -0.07
when t=9
do the same thing,
-0.07e^-0.05(9) ---use calculator
